NP-MRD: Showing NP-Card for 8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione (NP0281792)

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Record Information

Version

2.0

Created at

2022-09-09 08:21:38 UTC

Updated at

2022-09-09 08:21:38 UTC

NP-MRD ID

NP0281792

Secondary Accession Numbers

None

Natural Product Identification

Common Name

8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione

Description

8-Hydroxy-5,8a-dimethyl-3-methylidene-2H,3H,3aH,4H,6H,7H,8H,8aH,9H,9aH-naphtho[2,3-b]furan-2,6-dione belongs to the class of organic compounds known as eudesmanolides, secoeudesmanolides, and derivatives. These are terpenoids with a structure based on the eudesmanolide (a 3,5a,9-trimethyl-naphtho[1,2-b]furan-2-one derivative) or secoeudesmanolide (a 3,6-dimethyl-5-(pentan-2-yl)-1-benzofuran-2-one derivative) skeleton. 8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione is found in Inula japonica. 8-Hydroxy-5,8a-dimethyl-3-methylidene-2H,3H,3aH,4H,6H,7H,8H,8aH,9H,9aH-naphtho[2,3-b]furan-2,6-dione is an extremely weak basic (essentially neutral) compound (based on its pKa).

Structure

MOL 3D MOL SDF PDB SMILES InChI

     RDKit          3D

 37 39  0  0  0  0  0  0  0  0999 V2000
    3.7069    1.2203   -0.5719 C   0  0  0  0  0  0  0  0  0  0  0  0
    3.1263    0.1916    0.0601 C   0  0  0  0  0  0  0  0  0  0  0  0
    3.6154   -1.1593    0.1350 C   0  0  0  0  0  0  0  0  0  0  0  0
    4.7473   -1.5360   -0.2829 O   0  0  0  0  0  0  0  0  0  0  0  0
    2.6405   -1.9559    0.7360 O   0  0  0  0  0  0  0  0  0  0  0  0
    1.4326   -1.1948    0.8849 C   0  0  2  0  0  0  0  0  0  0  0  0
    0.4994   -1.6403   -0.1810 C   0  0  0  0  0  0  0  0  0  0  0  0
   -0.7290   -0.8245   -0.3406 C   0  0  2  0  0  0  0  0  0  0  0  0
   -1.2215   -1.0083   -1.7800 C   0  0  0  0  0  0  0  0  0  0  0  0
   -0.4525    0.5883   -0.0555 C   0  0  0  0  0  0  0  0  0  0  0  0
   -1.4982    1.4038    0.0112 C   0  0  0  0  0  0  0  0  0  0  0  0
   -1.3138    2.8353    0.2923 C   0  0  0  0  0  0  0  0  0  0  0  0
   -2.8511    0.8683   -0.1983 C   0  0  0  0  0  0  0  0  0  0  0  0
   -3.7510    1.5854   -0.6505 O   0  0  0  0  0  0  0  0  0  0  0  0
   -3.1361   -0.5532    0.1392 C   0  0  0  0  0  0  0  0  0  0  0  0
   -1.8724   -1.2750    0.5487 C   0  0  2  0  0  0  0  0  0  0  0  0
   -1.6160   -1.0344    1.8959 O   0  0  0  0  0  0  0  0  0  0  0  0
    0.8966    1.1541    0.1594 C   0  0  0  0  0  0  0  0  0  0  0  0
    1.8504    0.2246    0.8210 C   0  0  2  0  0  0  0  0  0  0  0  0
    3.2504    2.1981   -0.5643 H   0  0  0  0  0  0  0  0  0  0  0  0
    4.6278    1.0711   -1.0867 H   0  0  0  0  0  0  0  0  0  0  0  0
    1.0125   -1.4869    1.8704 H   0  0  0  0  0  0  0  0  0  0  0  0
    0.1969   -2.6874    0.0381 H   0  0  0  0  0  0  0  0  0  0  0  0
    1.0567   -1.6341   -1.1506 H   0  0  0  0  0  0  0  0  0  0  0  0
   -0.3997   -1.4061   -2.4245 H   0  0  0  0  0  0  0  0  0  0  0  0
   -2.0321   -1.7646   -1.8358 H   0  0  0  0  0  0  0  0  0  0  0  0
   -1.5116   -0.0379   -2.2344 H   0  0  0  0  0  0  0  0  0  0  0  0
   -0.8853    3.0286    1.3002 H   0  0  0  0  0  0  0  0  0  0  0  0
   -0.5446    3.2363   -0.4287 H   0  0  0  0  0  0  0  0  0  0  0  0
   -2.2749    3.3733    0.1651 H   0  0  0  0  0  0  0  0  0  0  0  0
   -3.8697   -0.6424    0.9770 H   0  0  0  0  0  0  0  0  0  0  0  0
   -3.5941   -1.0120   -0.7602 H   0  0  0  0  0  0  0  0  0  0  0  0
   -2.0054   -2.3731    0.3545 H   0  0  0  0  0  0  0  0  0  0  0  0
   -1.3351   -1.8915    2.3406 H   0  0  0  0  0  0  0  0  0  0  0  0
    0.8491    2.0860    0.7857 H   0  0  0  0  0  0  0  0  0  0  0  0
    1.2687    1.4899   -0.8349 H   0  0  0  0  0  0  0  0  0  0  0  0
    2.1167    0.5630    1.8655 H   0  0  0  0  0  0  0  0  0  0  0  0
 12 11  1  0
 11 10  2  0
 10 18  1  0
 18 19  1  0
 19  6  1  0
  6  7  1  0
  7  8  1  0
  8  9  1  6
  8 16  1  0
 16 17  1  0
 16 15  1  0
 15 13  1  0
 13 14  2  0
  6  5  1  0
  5  3  1  0
  3  4  2  0
  3  2  1  0
  2  1  2  3
 13 11  1  0
  8 10  1  0
  2 19  1  0
 12 28  1  0
 12 29  1  0
 12 30  1  0
 18 35  1  0
 18 36  1  0
 19 37  1  1
  6 22  1  1
  7 23  1  0
  7 24  1  0
  9 25  1  0
  9 26  1  0
  9 27  1  0
 16 33  1  1
 17 34  1  0
 15 31  1  0
 15 32  1  0
  1 20  1  0
  1 21  1  0
M  END


  Mrv1533004161519462D          

 19 21  0  0  0  0            999 V2000
    1.4289    0.8250    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    1.4289    0.0000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    2.1434   -0.4125    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    2.8579    0.0000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    3.5724   -0.4125    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    3.5724   -1.2375    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    2.8579   -1.6500    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    2.1434   -1.2375    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    2.1434   -2.0625    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    1.4289   -1.6500    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    1.4289   -2.4750    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
    0.7145   -1.2375    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    0.7145   -0.4125    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    0.0000   -0.0000    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
    4.3570   -1.4924    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
    4.8419   -0.8250    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    5.6669   -0.8250    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
    4.3570   -0.1576    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    4.6119    0.6271    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
  1  2  1  0  0  0  0
  2  3  2  0  0  0  0
  3  4  1  0  0  0  0
  4  5  1  0  0  0  0
  5  6  1  0  0  0  0
  6  7  1  0  0  0  0
  7  8  1  0  0  0  0
  3  8  1  0  0  0  0
  8  9  1  0  0  0  0
  8 10  1  0  0  0  0
 10 11  1  0  0  0  0
 10 12  1  0  0  0  0
 12 13  1  0  0  0  0
  2 13  1  0  0  0  0
 13 14  2  0  0  0  0
  6 15  1  0  0  0  0
 15 16  1  0  0  0  0
 16 17  2  0  0  0  0
 16 18  1  0  0  0  0
  5 18  1  0  0  0  0
 18 19  2  0  0  0  0
M  END
> <DATABASE_ID>
NP0281792

> <DATABASE_NAME>
NP-MRD

> <SMILES>
CC1=C2CC3C(CC2(C)C(O)CC1=O)OC(=O)C3=C

> <INCHI_IDENTIFIER>
InChI=1S/C15H18O4/c1-7-9-4-10-8(2)11(16)5-13(17)15(10,3)6-12(9)19-14(7)18/h9,12-13,17H,1,4-6H2,2-3H3

> <INCHI_KEY>
KJSSILWQFKEAFM-UHFFFAOYSA-N

> <FORMULA>
C15H18O4

> <MOLECULAR_WEIGHT>
262.305

> <EXACT_MASS>
262.12050906

> <JCHEM_ACCEPTOR_COUNT>
3

> <JCHEM_ATOM_COUNT>
37

> <JCHEM_AVERAGE_POLARIZABILITY>
27.038120935679707

> <JCHEM_BIOAVAILABILITY>
1

> <JCHEM_DONOR_COUNT>
1

> <JCHEM_FORMAL_CHARGE>
0

> <JCHEM_GHOSE_FILTER>
1

> <JCHEM_IUPAC>
8-hydroxy-5,8a-dimethyl-3-methylidene-2H,3H,3aH,4H,6H,7H,8H,8aH,9H,9aH-naphtho[2,3-b]furan-2,6-dione

> <ALOGPS_LOGP>
0.59

> <JCHEM_LOGP>
1.5141968586666668

> <ALOGPS_LOGS>
-2.04

> <JCHEM_MDDR_LIKE_RULE>
0

> <JCHEM_NUMBER_OF_RINGS>
3

> <JCHEM_PHYSIOLOGICAL_CHARGE>
0

> <JCHEM_PKA>
17.571975453206544

> <JCHEM_PKA_STRONGEST_ACIDIC>
14.443409414456085

> <JCHEM_PKA_STRONGEST_BASIC>
-3.0408003125681073

> <JCHEM_POLAR_SURFACE_AREA>
63.6

> <JCHEM_REFRACTIVITY>
69.058

> <JCHEM_ROTATABLE_BOND_COUNT>
0

> <JCHEM_RULE_OF_FIVE>
1

> <ALOGPS_SOLUBILITY>
2.39e+00 g/l

> <JCHEM_TRADITIONAL_IUPAC>
8-hydroxy-5,8a-dimethyl-3-methylidene-3aH,4H,7H,8H,9H,9aH-naphtho[2,3-b]furan-2,6-dione

> <JCHEM_VEBER_RULE>
0

$$$$

HEADER    PROTEIN                                 16-APR-15   NONE
TITLE     NULL                                                        
COMPND    NULL                                                        
SOURCE    NULL                                                        
KEYWDS    NULL                                                        
EXPDTA    NULL                                                        
AUTHOR    Marvin                                                      
REVDAT   1   16-APR-15         0                                  
HETATM    1  C   UNK     0       2.667   1.540   0.000  0.00  0.00           C+0
HETATM    2  C   UNK     0       2.667   0.000   0.000  0.00  0.00           C+0
HETATM    3  C   UNK     0       4.001  -0.770   0.000  0.00  0.00           C+0
HETATM    4  C   UNK     0       5.335   0.000   0.000  0.00  0.00           C+0
HETATM    5  C   UNK     0       6.668  -0.770   0.000  0.00  0.00           C+0
HETATM    6  C   UNK     0       6.668  -2.310   0.000  0.00  0.00           C+0
HETATM    7  C   UNK     0       5.335  -3.080   0.000  0.00  0.00           C+0
HETATM    8  C   UNK     0       4.001  -2.310   0.000  0.00  0.00           C+0
HETATM    9  C   UNK     0       4.001  -3.850   0.000  0.00  0.00           C+0
HETATM   10  C   UNK     0       2.667  -3.080   0.000  0.00  0.00           C+0
HETATM   11  O   UNK     0       2.667  -4.620   0.000  0.00  0.00           O+0
HETATM   12  C   UNK     0       1.334  -2.310   0.000  0.00  0.00           C+0
HETATM   13  C   UNK     0       1.334  -0.770   0.000  0.00  0.00           C+0
HETATM   14  O   UNK     0       0.000  -0.000   0.000  0.00  0.00           O+0
HETATM   15  O   UNK     0       8.133  -2.786   0.000  0.00  0.00           O+0
HETATM   16  C   UNK     0       9.038  -1.540   0.000  0.00  0.00           C+0
HETATM   17  O   UNK     0      10.578  -1.540   0.000  0.00  0.00           O+0
HETATM   18  C   UNK     0       8.133  -0.294   0.000  0.00  0.00           C+0
HETATM   19  C   UNK     0       8.609   1.171   0.000  0.00  0.00           C+0
CONECT    1    2                                                            
CONECT    2    1    3   13                                                  
CONECT    3    2    4    8                                                  
CONECT    4    3    5                                                       
CONECT    5    4    6   18                                                  
CONECT    6    5    7   15                                                  
CONECT    7    6    8                                                       
CONECT    8    7    3    9   10                                             
CONECT    9    8                                                            
CONECT   10    8   11   12                                                  
CONECT   11   10                                                            
CONECT   12   10   13                                                       
CONECT   13   12    2   14                                                  
CONECT   14   13                                                            
CONECT   15    6   16                                                       
CONECT   16   15   17   18                                                  
CONECT   17   16                                                            
CONECT   18   16    5   19                                                  
CONECT   19   18                                                            
MASTER        0    0    0    0    0    0    0    0   19    0   42    0
END

View in JSmol

Synonyms

Not Available

Chemical Formula

C₁₅H₁₈O₄

Average Mass

262.3050 Da

Monoisotopic Mass

262.12051 Da

IUPAC Name

8-hydroxy-5,8a-dimethyl-3-methylidene-2H,3H,3aH,4H,6H,7H,8H,8aH,9H,9aH-naphtho[2,3-b]furan-2,6-dione

Traditional Name

8-hydroxy-5,8a-dimethyl-3-methylidene-3aH,4H,7H,8H,9H,9aH-naphtho[2,3-b]furan-2,6-dione

CAS Registry Number

Not Available

SMILES

CC1=C2CC3C(CC2(C)C(O)CC1=O)OC(=O)C3=C

InChI Identifier

InChI=1S/C15H18O4/c1-7-9-4-10-8(2)11(16)5-13(17)15(10,3)6-12(9)19-14(7)18/h9,12-13,17H,1,4-6H2,2-3H3

InChI Key

KJSSILWQFKEAFM-UHFFFAOYSA-N

Experimental Spectra

Not Available

Predicted Spectra

Spectrum Type	Description	Depositor ID	Depositor Organization	Depositor	Deposition Date	View
1D NMR	¹³C NMR Spectrum (1D, 25 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹H NMR Spectrum (1D, 100 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹³C NMR Spectrum (1D, 252 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹H NMR Spectrum (1D, 1000 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹³C NMR Spectrum (1D, 50 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹H NMR Spectrum (1D, 200 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹³C NMR Spectrum (1D, 75 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹H NMR Spectrum (1D, 300 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹³C NMR Spectrum (1D, 101 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹H NMR Spectrum (1D, 400 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹³C NMR Spectrum (1D, 126 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹H NMR Spectrum (1D, 500 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹³C NMR Spectrum (1D, 151 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹H NMR Spectrum (1D, 600 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹³C NMR Spectrum (1D, 176 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹H NMR Spectrum (1D, 700 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹³C NMR Spectrum (1D, 201 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹H NMR Spectrum (1D, 800 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹³C NMR Spectrum (1D, 226 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum
1D NMR	¹H NMR Spectrum (1D, 900 MHz, H₂O, predicted)	Wishart Lab	Wishart Lab	David Wishart	2021-06-20	View Spectrum

Chemical Shift Submissions

Not Available

Species

Species of Origin

Species Name	Source	Reference
Inula japonica	LOTUS Database	35616633

Chemical Taxonomy

Description

Belongs to the class of organic compounds known as eudesmanolides, secoeudesmanolides, and derivatives. These are terpenoids with a structure based on the eudesmanolide (a 3,5a,9-trimethyl-naphtho[1,2-b]furan-2-one derivative) or secoeudesmanolide (a 3,6-dimethyl-5-(pentan-2-yl)-1-benzofuran-2-one derivative) skeleton.

Kingdom

Organic compounds

Super Class

Lipids and lipid-like molecules

Class

Prenol lipids

Sub Class

Terpene lactones

Direct Parent

Eudesmanolides, secoeudesmanolides, and derivatives

Alternative Parents

Substituents

Eudesmanolide
Sesquiterpenoid
Naphthofuran
Cyclohexenone
Gamma butyrolactone
Tetrahydrofuran
Alpha,beta-unsaturated carboxylic ester
Enoate ester
Carboxylic acid ester
Ketone
Lactone
Secondary alcohol
Cyclic ketone
Monocarboxylic acid or derivatives
Carboxylic acid derivative
Oxacycle
Organoheterocyclic compound
Hydrocarbon derivative
Carbonyl group
Organic oxide
Organic oxygen compound
Organooxygen compound
Alcohol
Aliphatic heteropolycyclic compound

Molecular Framework

Aliphatic heteropolycyclic compounds

External Descriptors

Not Available

Physical Properties

State

Not Available

Experimental Properties

Property	Value	Reference
Melting Point	Not Available	Not Available
Boiling Point	Not Available	Not Available
Water Solubility	Not Available	Not Available
LogP	Not Available	Not Available

Predicted Properties

Property	Value	Source
logP	0.59	ALOGPS
logP	1.51	ChemAxon
logS	-2	ALOGPS
pKa (Strongest Acidic)	14.44	ChemAxon
pKa (Strongest Basic)	-3	ChemAxon
Physiological Charge	0	ChemAxon
Hydrogen Acceptor Count	3	ChemAxon
Hydrogen Donor Count	1	ChemAxon
Polar Surface Area	63.6 Å²	ChemAxon
Rotatable Bond Count	0	ChemAxon
Refractivity	69.06 m³·mol⁻¹	ChemAxon
Polarizability	27.04 Å³	ChemAxon
Number of Rings	3	ChemAxon
Bioavailability	Yes	ChemAxon
Rule of Five	Yes	ChemAxon
Ghose Filter	Yes	ChemAxon
Veber's Rule	No	ChemAxon
MDDR-like Rule	No	ChemAxon

External Links

HMDB ID

Not Available

DrugBank ID

Not Available

Phenol Explorer Compound ID

Not Available

FoodDB ID

Not Available

KNApSAcK ID

Not Available

Chemspider ID

Not Available

KEGG Compound ID

Not Available

BioCyc ID

Not Available

BiGG ID

Not Available

Wikipedia Link

Not Available

METLIN ID

Not Available

PubChem Compound

75581906

PDB ID

Not Available

ChEBI ID

Not Available

Good Scents ID

Not Available

References

General References

LOTUS database [Link]

Showing NP-Card for 8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione (NP0281792)

MOL for NP0281792 (8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione)

3D MOL for NP0281792 (8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione)

3D SDF for NP0281792 (8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione)

3D-SDF for NP0281792 (8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione)

PDB for NP0281792 (8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione)

3D PDB for NP0281792 (8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione)

SMILES for NP0281792 (8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione)

INCHI for NP0281792 (8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione)

Structure for NP0281792 (8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione)

3D Structure for NP0281792 (8-hydroxy-5,8a-dimethyl-3-methylidene-3ah,4h,7h,8h,9h,9ah-naphtho[2,3-b]furan-2,6-dione)